The Quest Tracking System, which is often abbreviated as the QTS, is a block added by Hardcore Questing Mode that is used to emit a redstone signal based on the completion of a quest. It is unobtainable in survival, as it is only used for mapmaking purposes.
Once placed in the world, the QTS can be bound to any type of Quest by having that quest open in the Quest Book, and then right-clicking on the QTS. It can also be bound via the use of the Select Quest tool. Once bound, right clicking on it without the book presents a variety of options. The map creator can choose to have it output a signal whose strength varies depending on the individual completion of the quest,on the overall completion of the quest, and on the team completion of a quest.
There is also an option to have it only output a signal based on the completion of players within a designated radius.